A wire throttle adjustment mechanism is configured to perform open-close adjustment of a throttle valve from an idling state to a fully-opened state by using a wire to pull the throttle valve, which is biased in a closing direction by elastic force of a spring, against the elastic force of the spring. Such a throttle adjustment mechanism has been broadly employed as an output adjustment mechanism in a compact engine-driven handheld or backpack machine (a chain saw, a hedge trimmer, a brush cutter, a blower/vacuum blower, and a sprayer/duster).
This wire throttle adjustment mechanism includes, near a handle or a grip, an operation member configured to pull the wire (a throttle lever, a throttle trigger, etc.). Such an operation member includes a pivotally-supported part that is swingably and pivotally supported on a housing of a holding part, a wire connection part connected to an end part of the wire, and an operation part (a gripping part) configured to swingably operate the operation member about a shaft with, e.g., a finger (see Patent Literature 1 below).
When the throttle lever is operated to adjust opening/closing of the throttle valve via the wire or a cable, an appropriate idling position and an appropriate fully-opened position (a full throttle position) of the throttle valve need to be set within an operation range of the throttle lever. Therefore, in a prior-art case, a position adjustment device is provided at a relay point of the wire, thereby appropriately adjusting an opened/closed position of the throttle valve so as to fall within the operation range of the throttle lever (see Patent Literature 2 below).